Remove a dead variable from ldmd. (It used to be used to pass an extra -help to ldc when no files were specified, but we handle that in ldc itself now)

void main()
{
    float m[4][4];

    float* fp = &m[0][0];
    for (int i=0; i<16; i++,fp++)
        assert(*fp !<>= 0);
}